Virginia rails () are migratory birds whose range includes central and southern North America. Their breeding range reach as far north as New Brunswick, Canada, as far west as the Pacific coast, and as far east as Philadelphia, Pennsylvania, with gaps in Wyoming, Utah and Montana.
Their non-breeding range can be found along the eastern coast of the United beginning in North Carolina traveling southward toward the Gulf of Mexico. There are also populations along the western coast of the United States, but it is limited to central Arizona and stretches southward to the Baja Peninsula. This range also includes central Mexico, including both of its coasts. Wintering populations also are found in South America, specifically Colombia, Ecuador, Peru, Chile, and Argentina.
Populations of this species has been known to be found year-round in parts Arizona, the coast of California, the northern tip of Washington State, and eastern Virginia. There have even been rare sightings of the Virginia rail in Bermuda and Greenland. This species has one subspecies (Rallus limicola limicola) that is limited to the Mexican Plateau. (BirdLife International, 2012; Conway, 1995; Glisson, et al., 2015)
Virginia rails are known to inhabit elevations between 0 and 2,370 m (the upper limit in Peruvian mountains). During their breeding season Virginia rails can be found in lower elevations, mostly in freshwater marshlands with an adequate concentration of emergent vegetation (between 40 cm and 100 cm), such as cattails (Typha) and bulrush (Scirpus). They are found mostly in shallow to intermediate waters (0 to 15 cm) and frequent mudflats. They avoid deeper waters (20 to 40 cm), but will inhabit these areas if there is a sufficient amount of fallen of floating vegetation on which they can walk and forage.
Their winter habitat is similar to that of their breeding habitat except for those who live in Arizona. That populations moves away from the open waters of the marshes to marshy habitats with more cover and with emergent vegetation height that exceeds 100 cm. (Benoit and Askins, 2002; Conway, 1995; Dinsmore and Johnson, 1986; Griese, et al., 1980)
Virginia rails are marshland birds with a mass of 55 to 124 g across both sexes. Females are generally smaller than males, with a mass between 64 g and 77 g and a wingspan between 89 mm and 106 mm. Males have an average weight between 79 g and 104 g, with an average wingspan of 99 mm and 113 mm. In length they range from 22 to 27 cm. Their body feathers, legs and bill are all reddish brown in color and their cheek feathers are gray in color. Their chestnut wings contain a small (1 mm) claw on the fifth digit.
Hatchlings begin with black down feathers. Their first molt begins at about 2 weeks of age. By 6 weeks, they have their full juvenal plumage, which is a little duller and less contrasting than breeding adult plumage. Juveniles can be further identified by the pale pink color on their bills and a black band on the distal end of the upper mandible. The irises of juveniles are black at hatching but changes to brown during development and eventually reddish brown in adults. The skin around the eyes of chicks is a dark bluish-black. This color is also found of most of their head as well. By the time the juveniles depart for fall migration, their plumage matches that of the adults. Adult males and females look alike.
Of note, rails are reported by Conway (1995) as possessing the highest leg muscle to flight muscle ratio of any bird group. This ratio probably explains why they are adapted to running (strong leg muscles) and poor, brief fliers. (Bolenbaugh, et al., 2011; Conway, 1995; Feduccia, 1968)
Virginia rails are monogamous. Their courtship is very brief and is recognized by the tick-it calls heard within the territory. Either sex can initiate this courtship. Part of the courtship, lasting up to 2 weeks, is silently standing side-by-side 30-minute blocks of time. Males perform a dance where they run in circles around the females with their wings raised above their bodies and they flit their tails, bowing in the front of the females with each pass.
Once a pair bond is formed they engage in the preening of themselves and their mate (called autopreening and allopreening, respectively), chasing each other around their nesting area, and the actual act of mating. They exchange calls, engage in courtship feeding and defend their territory together. In captive studies, mating was noted 20 days before the first egg was laid and stopped after the last egg was laid.
Nest building begins about one week before the first egg is laid, usually in early May. The nest is made with whatever plants are most available, like cattails Typha or bulrush Scirpus. The outer diameter of the nest was reported as 17.3 cm (Conway, 1995). The thickness of the vegetation surrounding the nest provides adequate cover and concealment from predators. The nest is not typically made near open water but is relatively close to shallow water with emergent vegetation.
The pair bond can last longer than the bond between the parent and its young, but it breaks before their migration or right after their young fledge. (Conway, 1995)
The breeding season for the Virginia rails begins in early April and can last until early September. During this time paired Virginia rails can have up to two broods each with a range of 4 to 13 eggs (mean 8.5). Clutch size of populations in the northern end of the region tends to be higher than populations further south.
Nesting females lay one egg per day and the first egg can be found as early as the first week of April to as late as mid-July. Depending on latitude, the peak of egg-laying is in May or June. The incubation period lasts about 19 days. During the incubation period partners feed one another. Forty-eight hours before hatching the eggs begins to crack and peeping can be heard from within. It can take the chick up to thirty-six hours to break free from its shell. Most hatchings are synchronous in that they follow each other within the next two days after the first hatching.
Chicks are precocial with a mean mass of about 5.4 grams at birth and range from 5.0 grams to 5.8 grams. It is thought that the young gain 1.5 g to 3 g of body mass per day (Conway, 1995). They can preen themselves and their siblings within four hours post-hatching and eat within the first two hours. Virginia rail chicks are completely covered in black down. They have a 1-mm black band at the center of their bill and a white egg tooth that stays for the first two weeks post-hatching.
Virginia rail chicks develop quickly. By the end of their first day post-hatching, chicks can stand, preen, drink, and swim. They leave the nest with four days of hatching. Adult behaviors such as probing for food, aggression among nest mates, nest-building behavior, and play-fighting are achieved by day 23. Young Virginia rails can fly by four weeks old. They become independent from parents by age 4-6 weeks. It is around this time that it is also believed that they gain their sexual maturity. They can certainly breed in their first year of life. (Conway, 1995; Johnson and Dinsmore, 1985)
Virginia rails show parental investment. Both parents incubate the eggs in alternating shifts every one to two hours, though it has been found that females incubate 60-80% of the time. They are both there during the hatching and help the chicks leave the egg by removing pieces of the shell from the nest. Brooding of the chicks last about two weeks in which both parents feed their young. They keep the chicks near the nesting area for the first 3-4 weeks, but chicks slowly expand their range as they gain independence. Both parents also aggressively defend their young when in danger. They bow their heads and outstretch their necks calling out regular rasping calls to deter intruder. Females are more aggressive than males when defending young. (Conway, 1995; Johnson and Dinsmore, 1985)
Do to the secretive nature of Virginia rails not much is known about its lifespan. Other Rallus species, such as the clapper rail (Rallus longirostris) and the water rail (Rallus aquaticus) live on average 8-9 years. In two studies, annual survivorship was 52 to 53% across all seasons and age groups, but mortality was highest in the winter. It's believed that mortality is highest before chicks read the fledgling stage. (AnAge, 2016; Conway, 1995)
Virginia rails are crepuscular, foraging at dawn at dusk. Due to poorly-developed flight muscles combined with very strong leg muscles, they are found predominantly on the ground, walking, hopping, or running. They do fly during migration though not for very long intervals, and their landings are rather clumsy-looking and rough. While walking, these birds hold their tails up and fan them. In doing, so, their covert feathers, which are black and white, are displayed. They can also swim and dive but mostly do this to evade predators.
During the breeding season Virginia rails are solitary, but have a tolerance towards soras (Porzana carolina) in their territories. Virginia rails are territorial during their establishment and pair formation period, and aggresively defend their nests. However, there is a trade-off; in vigorously defending their nests, they are less apt to defend the outer boundaries of their territory. They do not defend territories in winter months.
Due to territory overlap with soras (Porzana carolina) and the variation found in seasonal habitats, it is difficult to average the Virginia rails home range. It is thought to be similar in size to that of their breeding territory. The breeding territory of the Virginia rails follows the boundary of emergent plants that lay upland of open waters shaped like a "V." A study in Arizona found that during the breeding season, a pair's home range was 1.64 ± 1.48 ha and 2.41 ± 1.84 ha during the winter. In Iowa, pairs only used 0.18 ha in the breeding season (Conway, 1995). It's unclear how much of their home range they actively defend, but Conway (1995) reports that some individuals only defend their immediate nest area during the breeding season. (Conway, 1995; Johnson and Dinsmore, 1985)
Conway (1995) summarized four types of calls primarily used by adult Virginia rails: grunts, tick-its, kickers and kius. A duetting grunt is used by pairs to identify one another. It also serves to identify neighbors and in terrestrial defense against aggressive males. Their "tick-it" (Glahn, 1974) calls are heard by males during the spring and may be linked to mating because soon after a "tick-it" call is answered by a "kicker" (Glahn, 1974) call the duetting grunts are all that can be heard in the area. A "kiu" (Conway, 1995) call is thought to be a sound of alarm and can be made by both sexes.
Chicks can emit a "pee-eep" (Conway, 1995) sound when separated from the brood and in response the adult will give off a low-pitched call in return.
Due to the large number of nasal glands and ducts in the olfactory chamber and their large olfactory bulb found in their brain it is thought that Virginia rails have a highly developed sense of smell. (Conway and Gibbs, 2011; Conway, 1995; Glahn, 1974)
During the breeding season, Virginia rails eat small invertebrates such as beetles, snails, spiders, earthworms and fly (Diptera) larvae. Animal parts make up 85-97% of the summer diet. They mainly forage in shallow waters or mudflats using their bills to probe the waters in a swift and uninterrupted succession. If the water is deep (more than 20 cm) they have been found to stand on floating marsh reeds to forage for aquatic invertebrates, such as crayfish, as well as small vertebrates such as frogs, small fish and snakes.
In the winter months their diet is more plant-based, making up 20-30% of total diet. They will feed on the seeds of marsh plant such as pondweed (Potamogeton), cowlily (Nuphar polysepala) or wild rice (Zizania). The remaining food items in winter are aquatic invertebrates. (Baschuk, et al., 2012; Conway, 1995)
Virginia rails are susceptible to a range of predatory mammals, birds, and even amphibians. Birds that prey on nests include wrens, hawks, American crows (Corvus brachyrhynchos), yellowed-billed cuckoos (Coccyzus americanus). Predatory mammals that consume eggs and nestlings are ermines (Mustela erminea), muskrats (Ondatra zibethicus), raccoons (Procyon lotor), striped skunks (Mephitis mephitis), and American mink (Neovision vision). Snakes also feed on nest inhabitants.
Young chicks are preyed upon by pike (Esox), sandhill cranes (Grus canadensis), frogs, and bass. Great egrets (Ardea alba), coyotes (Canis latrans), feral cats (Felis catus), owls, and northern harriers (Circus cyaneus) have been found to prey on adults and juveniles.
To defend themselves and their young adult Virginia rails will perform distraction displays with their wings lowered body forward, and run in tight circles around the nest or submerge theirs bodies into water. They also give out their kiu alarm calls. (Conway, 1995)
Virginia rails compete for space with soras (Porzana carolina) and other rails. Virginia rails carry external parasites such as lice (Pseudomenopon pacificum) and bird flies (Lynchia). Nasal mites include Rallinyssus verheyeni. They are also known to carry nematodes, cestodes and trematodes. (Conway, 1995; Pence, 1972; Peters, 1936)
Very few hunters hunt rails but thirty-seven states and one province (Ontario, Canada) list Virginia rails as a game species. Rail hunting season is during the fall from early September to mid-November. As of 2015, an average of 26,800 rails where harvested by hunters in the U.S. (Conway, 1995)
There are no adverse effects ofon humans.
Virginia rails are listed as a species of "Least concern" on the IUCN Red List. It was also found that from 1991-1996 there was a 0.2% increase in the population in Canada. Also during this time there was a -0.4% decrease in the Virginia rails population in the United States, with -0.2% in North America alone (Conway, Eddleman, and Anderson, 1994).
Under the US Migratory Bird Act Virginia rails are listed as "Protected." This act makes it illegal for anyone to buy, sell, transport, or export any migratory bird without the valid permit revived through Federal regulations. They hold no special status under the US Federal List, CITES, or the State of Michigan List. They are listed as a species of concern in Virginia and Ohio, and endangered in Indiana.
Threats to survival include hunting (although hunting pressure is likely low across their range), bioaccumulation of mercury, and collisions with human-made structures.
Conservation measures are typically not directed towards Virginia rails, but this species benefits from wetland management that maintains emergent vegetation and does not greatly alter water levels during the nesting season. Daily bag limits in hunting states typically are set at 25 birds/day, and it's not thought that hunting affects the sustainability of these birds. (BirdLife International, 2012; Conway, 1995; Conway, et al., 1994)
Essence Elbert (author), Radford University, Alex Atwood (editor), Radford University, Marisa Dameron (editor), Radford University, Karen Powers (editor), Radford University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
active at dawn and dusk
to jointly display, usually with sounds in a highly coordinated fashion, at the same time as one other individual of the same species, often a mate
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
A substance that provides both nutrients and energy to a living thing.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
parental care is carried out by males
marshes are wetland areas often dominated by grasses and reeds.
makes seasonal movements between breeding and wintering grounds
Having one mate at a time.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
an animal that mainly eats all kinds of things, including plants and animals
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.
breeding is confined to a particular season
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
uses sight to communicate
young are relatively well-developed when born
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